Improvement in the manufacture of leather-board



UNITED STATES PATENT OFFIOE.

STEPHEN MOORE, OF SUDBURY, MAsSAOHUsETTs,' AssroNo To HIMSELF AND HOMER ROGERS, OF SAME PLACE.

IMPROVEMENT IN THE MANUFACTURE OF LEATHER-BOARD Specification forming part of Letters Patent No. I 39,598, datgd J one 3, 1873; application filed March 5, 1873. I I

To all whom it may concern:

Be it known that I, STEPHEN MOORE, of Sud bury, in the county of Middlesex and State of Massachusetts, have invented an Improve ment in the Manufacture of Leather-Board, &c.; and I do hereby declare that the following is a description of my invention sufficient "to enable those skilled in the art to practice In the manufacture of pasteboard, cardboard, and leather-board, it is customary to wind the sheet of pulp in coils or layers upon a cylinder, cutting, slitting, and opening the tube thus formed, to make the sheet of board,

the board being subsequently passed through calender-rolls to dry it, andto harden and solidify its surfaces, and to compact the fibers throughout the sheet. The layers Owe their adhesiveness to the pulpy condition of the run W Inaterialg s tl ela y e ggrg unrtednnponthecylinder.

For the many purposes for which the leather-board is now used, a great degree of tensile strength is requisite, and the board, as usually made, is liable to I crack and break open at the surfaces, if subjected to much bending. To remedy this very good stock has to be used, but board made from such stock will not sell on account of its high cost.

The purpose of my invention is to strengthen the boardwithout increasing its cost, and

or apron, and conduct it to and wind it upon the cylinder, and, having wound a sufficient number of layers, I then take upon the apron the stock from the vat containing the weaker pulp, or the pulp to form the body or filling, and conduct this to and wind it upon the cyl inder around the coil already wound upon it. Having coiled enough stock to form the filling I disconnect the felt or apron from the filling vat, and again connect it with the vat con tainin g the surface-stock, and conduct the sheet of pulp to the cylinder and wind around the filling, the adjacent surfaces of the different grades of material uniting in precisely the same manner that the layers of the same material unite. I

By these meansI obtain a very perfect board, possessing a greater degree of strengthkhaii can be obtained without making the whole board of Stock as perfect as is the stock formin g the outer surfaces of the board. The skin upon each side of the filling may be made of any desirable degree of thickness as compared to the thickness of the filling, in accordance with the nature of the stock and the gree of strength required. I prefer to make the filling of about twenty to thirty layers,-

and each skin or outer surface of about ten layers. I claim- The improvement in the manufacture of leather-board, consisting in forming the board with a filling surfaced by the layers upon the cylinder, substantially as described.

Executed this 7th day of January, A. I).

STEPHEN MOORE.

Witnesses:

FRANCIS GOULD, M. W. FROTHINGHAM. 

